pin django to 1.4.x stream

django 1.5 just released in the last hour, and there is a
compatibility issue with it and horizon causing gate failures.

Pin this so that we can get back to business and let the horizon
team address django 1.5 when it makes sense to them.

Change-Id: I6ddf9623f8a4719b1cb82b118c1876373051fd28
(cherry picked from commit 0d53dc7063003fa7f02c030fd1631e0cd553d22a)
Allow permissions to be set on tables

Sometimes we want to hide certain UI elements depending on the
permissions granted to the current user. At the moment this is
possible for Actions and Panels. This commit extends support to
DataTable too.

We also set the permission on the volume snapshots table so that,
like the volumes panel, it is only displayed when the 'volume'
service is active.

Fixes bug #1087128.
(cherry-picked from commit eab5fc7712ce9c0b0e226a059f054773426ad6ae)
Fix table tests on stable/folsom